JP4333308B2 - U type steel sheet pile - Google Patents

Description

  The present invention relates to a U-shaped steel sheet pile, and more particularly to a U-shaped steel sheet pile that facilitates stacking while ensuring joint performance and workability.

Conventional U-type steel sheet piles, for example, generally have a Larsen type joint described in Non-Patent Document 1, and currently in domestic steel sheet piles, II, III, and IV types with a joint flange inclination θ1 of about 4 to 6 °. And the old groups of IIw, IIIw, IVw, VL, and VIL, where θ1 is about 12 to 18 °. Further, in Patent Document 1, there is a U-shaped steel in which protrusions that are independent or continuous in the longitudinal direction are formed on the side surface of the U-shaped steel in order to solve the problem of being stuck at the time of superposition such as a loaded state. It is disclosed.
Japanese Utility Model Publication No. 62-99631 Steel Pipe Pile Association “Steel Sheet Pile Standard Product Specification”

  The old group and the wide group have their advantages and disadvantages, and the old group has excellent joint performance, but is inferior in stacking performance (space efficiency, stability of posture, ease of separation one by one). On the other hand, the wide group is superior in stacking performance, but is considered inferior in joint performance.

  First, in order to evaluate the joint performance, for example, as shown in FIGS. 3 (a) and 3 (b), the difficulty of removing the nail is represented by the amount of nail hook (hook length of the nail) G. If the magnitude of the placement resistance is defined as a joint margin and expressed by the claw rotation angle α, the past performance can be evaluated with high accuracy. The claw engagement amount G and the claw rotation angle α vary depending on the joint opening width (width of the joint opening), the joint flange inclination, and the claw joint thickness. Here, as shown in FIG. 3 (c), the joint opening width is the difference between the radius R11 of the circle in contact with the outer surface of the flange around the center of curvature of the radius of the claw tip (: bending) and the curvature radius R1 of the same radius ( = R11-R1). Further, the joint flange inclination θ1 is defined by the intersection angle between the outer surface of the joint flange and a plane orthogonal to the claw bottom surface. The back surface of the claw was parallel to the outer surface of the joint flange (inclination of the back surface of the claw = joint flange inclination θ1). The nail joint thickness is defined by the difference (= R22−R2) between the radius R22 of the circle in contact with the outer surface of the nail joint centered on the center of curvature of the radius of the inner surface of the nail joint and the radius of curvature R2 of the same radius.

  From the illustrations of Figs. 3 (b) and 3 (a), the nail joint thickness (= R22-R2) is a constant value and the joint opening width (= R11-R1) and joint flange inclination θ1 are varied. A rotation angle α and a hooking amount G were obtained. The results are shown in FIGS. From these figures, as the joint opening width increases, the claw rotation angle α increases (FIG. 4), but the claw hook amount G decreases (FIG. 5). The condition for achieving joint performance is considered to be the joint opening width range (joint opening width tolerance) that satisfies both necessary values (for example, claw rotation angle α ≧ 36 °, claw hook amount G ≧ 6 mm). As shown in FIG. 6, the allowable opening width range is wider as the joint flange inclination θ1 is smaller. Therefore, if the joint flange inclination θ1 is large, the joint opening width range that satisfies the joint performance will be narrowed, and the target performance will have to be lowered due to manufacturing variations, etc., or the product yield that falls within the allowable range will be reduced. There is a problem that causes disadvantages.

If the joint flange inclination θ1 is reduced so that such a problem does not occur, the joint performance is excellent. However, when stacked in a stacked manner as shown in FIG. Not only will the posture become unstable, but it will also be elastically deformed by the wedge effect, and it will be difficult to separate one by one due to the tightness caused by the rigidity. For this reason, the IV type or the like may be a combination of coupling as shown in FIG. When considering a cross-sectional shape that prioritizes stacking performance, as shown in FIG. 8, if the joint flange inclination θ1 is made larger than sin ⁻¹ (joint flange thickness tf1 / joint height), the joint height Can be stacked in a stable posture at a stacking step interval h0 equal to. However, there is a possibility that the upper and lower joint portions come into contact with each other, and the lower claw is excessively pressed at the upper nail bottom and deformed.

  In the U-shaped steel sheet pile having the above-mentioned conventional Larzen type joint, the joint flange inclination θ1 belongs to one of two groups of large and small, so that the joint performance is excellent but the stacking performance is difficult, or It can be said that the performance of the stack was excellent but the joint performance was difficult. In addition, although the U-shaped steel of patent document 1 is improving the performance of stacking by providing a protrusion on the flange side surface, in order to provide such a protrusion, after hot rolling using a perforated roll, Since it is necessary to add rolling using the upper and lower horizontal rolls and the left and right female rolls with female protrusions, there is a problem that the manufacturing cost increases.

  Therefore, the present invention can be manufactured by hot rolling using a perforated roll, has a joint shape that is excellent in joint performance, adapted for stacking, and has a small joint flange inclination θ1. It aims at providing the U-shaped steel sheet pile which is excellent in performance.

The present invention relates to a U-shaped steel sheet pile manufactured by hot rolling using a perforated roll and having joints connected to both ends of the flanges on both sides of the web. Rutotomoni provided a recessed step portion and the bulges of the inner surface extending in the sheet pile longitudinally by an outer surface side of the recess and recess only to sit joint of the sheet pile, stage overlapped isomorphic steel sheet pile of the mating said recessed step It is a U-shaped steel sheet pile in which the inclination of the flanges on both the upper and lower sides of the concave stepped portion is set so as to be in contact with the rounded starting portion of the outer surface of the flange portion on the web side . Also, in the present invention, following the joint flange inclination θ1 is the slope of the lower flange of the recessed step portion and 10 ° or less, the web-side flange inclination θ2 is the slope of the upper flange of the recessed step portion It is preferably given by the formula (1).

θ2 ≒ Ψ = sin ^-1 (tf2 / h0) (1)
tf2: Flange thickness of the same type steel sheet pile as the stacking partner at the contact point with the radius starting point on the outer surface of the web side flange h0: Stacking step interval where “≒” is the allowable error range of θ2. It means that it is within ± 0.5 ° of the calculated value on the right side.

  In the U-shaped steel sheet pile of the present invention, a concave shape for seating the joint part (particularly, the joint end part of the joint steel sheet pile) of the mating steel sheet pile of the mating counterpart at the position on the joint part side of the left and right flanges respectively connected to the left and right mold joints. A step was provided. The height direction positions of the left and right concave stepped portions are the same. Thus, even when the joint flange inclination θ1 is small, the joint portion of the mating steel sheet pile is supported by the left and right concave stepped portions, and the mating of the mating steel sheet pile downward is effectively prevented. Therefore, an orderly stacked stacking appearance can be stably obtained, and it becomes easy to separate one by one from the stacked state. This concave stepped portion has a recess on the outer surface side and a bulge on the inner surface side due to the recess extending in the longitudinal direction of the steel sheet pile, and its cross-sectional shape can be shaped by bending the entire flange thickness Therefore, it can manufacture by the hot rolling using a perforated roll, and the additional shaping | molding process using a horizontal roll and a reed roll is unnecessary.

  However, only the left and right concave stepped portions support the joint portion of the mating steel sheet pile when the right or left joint portion of the mating steel sheet pile is detached from the concave stepped portion. Therefore, by setting the inclination of the flanges on both the upper and lower sides of the concave stepped portion so that the mating steel sheet pile simultaneously contacts the concave stepped portion and the radius starting portion of the outer surface of the web-side flange, They can be brought into contact with each other, and more stable stacking becomes possible. The contact at the four cross-sections can be reliably achieved by, for example, θ1 ≦ 10 ° and θ2≈Ψ, that is, Ψ−0.5 ° ≦ θ2 ≦ Ψ + 0.5 °.

  The U-shaped steel sheet pile of the present invention is best manufactured by hot rolling using a perforated roll in terms of manufacturing cost. The smaller the joint flange inclination θ1 is, the better from the viewpoint of joint performance (see FIG. 5). However, if the joint flange inclination θ1 is too small, the roll hole mold whose dimensions are not suitable due to roll wear or the like is returned to the original dimensions. The diameter drop amount of the roll becomes too large, resulting in deterioration of the roll basic unit. Incidentally, FIG. 9 shows the relationship between the hole-shaped restoration return roll cutting amount (cutting amount per 1 mm of wear) and the joint flange inclination θ1, and as shown in this figure, the joint flange inclination θ1 is If the angle is less than 4 °, the hole-type restoration roll cutting amount increases sharply, so the joint flange inclination θ1 is preferably 4 ° or more.

  The stacking step interval h0 is preferably larger than the joint height. Thereby, it can prevent that the joint part of an upper-lower stage mutually contacts, and it can prevent that a nail | claw deform | transforms with the pressing force by this mutual contact.

  FIG. 1 is a sectional view showing Example 1 (applied to the IV type in this example) in which the present invention is applied to the U-type steel sheet pile of the old group. In the figure, only the left portion of the sheet pile width center line 20 is shown, and the right portion symmetrical to this is omitted. In the U-shaped steel sheet piles 10 and 10a of this example, a claw bottom 3 of a joint portion is connected to both ends of the flange 2 on both sides of the web 1, and the flange 2 is provided with a concave step portion 2b. This concave stepped portion 2b has a recess on the outer surface side of the flange 2 and a bulge on the inner surface side due to the recess extending in the steel sheet pile longitudinal direction (direction perpendicular to the paper surface). It was formed by hot rolling. The concave step 2b has a lower end connected to the joint-side flange 2c and an upper end connected to the web-side flange 2a. The height from the lower end of the nail bottom 3 to the upper end of the flange 2c on the joint side is 30 mm larger than the height of the joint (the distance from the lower end surface of the nail bottom 3 to the upper end surface of the nail 4). set equal to h0.

The radius on the outer surface side of the flange 2 of the concave step portion 2b is substantially equal to the radius on the outer surface side of the joint 6 at the joint start end 5, and the joint flange inclination θ1 is obtained when the joint portion is translated in the height direction by a distance h0. Further, the outer surface of the joint 6 at the joint start end portion 5 after the movement is substantially overlapped with the outer surface of the flange 2 of the concave step portion 2b before the movement, and is set to 5 ° in this example. Further, the web-side flange inclination θ2 is such that the U-shaped steel sheet pile 10a with which the stacking counterpart is in contact with not only the concave stepped portion 2b of the U-shaped steel sheet pile 10 but also the radius starting point P of the outer flange surface on the web side, The range of sin ⁻¹ (tf2 / h0) −0.5 ° to sin ⁻¹ (tf2 / h0) + 0.5 ° was set so as to be supported by the left and right four points. Here, tf2 is the flange thickness of the mating steel sheet pile (for example, U-shaped steel sheet pile 10a) at the point of contact P with the radius starting point. h0 is the stacking step interval. Further, ± 0.5 ° is a value expected as an allowable range of manufacturing error. In this example, sin ⁻¹ (tf2 / h0) = 9.4 °.

  When the U-shaped steel sheet piles of this example were stacked in three stages, an orderly stacking shape without inclination was obtained, and the work of separating the sheets one by one from this stacked state could be performed very easily.

  If θ1 is made small in order to improve joint performance, stacking is not easy even in the U-shaped steel sheet pile of the wide group. FIG. 2 is a sectional view showing Example 2 (applied to the VL type in this example) in which the present invention is applied to the U-shaped steel sheet pile of the wide group. In the figure, only the left portion of the sheet pile width center line 20 is shown, and the right portion symmetrical to this is omitted. The U-shaped steel sheet piles 10, 10 a and 10 b of this example are formed by connecting claw bottoms 3 of joint portions to both ends of the flange 2 on both sides of the web 1, and the flange 2 is provided with a concave stepped portion 2 b. This concave stepped portion 2b has a recess on the outer surface side of the flange 2 and a bulge on the inner surface side due to the recess extending in the steel sheet pile longitudinal direction (direction perpendicular to the paper surface). It was formed by hot rolling. The concave step 2b has a lower end connected to the joint-side flange 2c and an upper end connected to the web-side flange 2a. The height from the lower end of the nail bottom 3 to the upper end of the flange 2c on the joint side is 1 mm larger than the height of the joint (the distance from the lower end surface of the nail bottom 3 to the upper end surface of the nail 4). set equal to h0.

The radius on the outer surface side of the flange 2 of the concave step portion 2b is substantially equal to the radius on the outer surface side of the joint 6 at the joint start end 5, and the joint flange inclination θ1 is obtained when the joint portion is translated in the height direction by a distance h0. In this example, the angle is set to 6 ° so that the outer surface of the joint 6 at the joint start end portion 5 after the movement substantially overlaps the outer surface of the flange 2 of the concave step portion 2b before the movement. Further, the U-shaped steel sheet piles 10a and 10b with which the web-side flange tilts θ2 are simultaneously contacted not only with the concave step portion 2b of the U-shaped steel sheet piles 10 and 10a but also with the radius starting point P on the outer flange surface of the web side. Thus, the range of sin ⁻¹ (tf2 / h0) −0.5 ° to sin ⁻¹ (tf2 / h0) + 0.5 ° was set so as to be supported at four points, upper and lower and left and right. Here, tf2 is the flange thickness of the mating steel sheet pile (for example, U-shaped steel sheet pile 10b) at the contact point P with the radius starting point. h0 is the stacking step interval. Further, ± 0.5 ° is a value expected as an allowable range of manufacturing error. In this example, sin ⁻¹ (tf2 / h0) = 17.8 °.

  When the U-shaped steel sheet piles of this example were stacked in three stages, an orderly stacking shape without inclination was obtained, and the work of separating the sheets one by one from this stacked state could be performed very easily.

  The U-shaped steel sheet pile of the present invention is a steel sheet pile having a small θ1 with improved joint performance regardless of the old group and the wide group, and can improve the stacking efficiency.

It is sectional drawing which shows Example 1 which applied this invention to the U-shaped steel sheet pile of an old type group. It is sectional drawing which shows Example 2 which applied this invention to the U-shaped steel sheet pile of a wide group. (A) and (b) are explanatory diagrams for defining the amount of nail hook G and the nail rotation angle α as evaluation indexes for joint performance, and (c) are the joint opening width (: R11-R1) and the nail joint thickness (: R22- R2) is a diagram illustrating the definition of the joint flange inclination θ1. 6 is a graph showing the relationship between the joint opening width and joint flange inclination θ1 and the claw rotation angle α. 5 is a graph showing the relationship between the joint opening width and joint flange inclination θ1 and the hook amount G. It is a graph which shows the relationship between joint part flange inclination (theta) 1 and a joint opening width | variety tolerance | permissible_range. It is sectional drawing which shows the example which piled up the steel sheet pile which has the conventional Ralzen type | mold joint with small joint part flange inclination (theta) 1, (a) is stacked, (b) shows the state of coupling stack. It is sectional drawing which shows the example which piled up the steel sheet pile which has the conventional Larsen type | mold joint with large joint part flange inclination (theta) 1. It is a graph which shows the relationship between a hole shape restoration | recovery return roll cutting amount, and joint part flange inclination (theta) 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Web 2 Flange 2a Flange 2b on the web side 2b Concave step 2c Flange on the joint side 3 Claw 4 Claw bottom 5 Joint start end 6
10, 10a U type steel sheet pile
20 Sheet pile width center line

Claims (2)

A U-shaped steel sheet pile manufactured by hot rolling using a perforated roll and having joints connected to both flange ends on both sides of the web. and bulges of the inner surface side by indentations and recess only the outer surface side to sit is provided a recessed step portion extending in the sheet pile longitudinally Rutotomoni, stage overlapping said is isomorphic steel sheet pile of the mating recessed step portion and the web-side A U-shaped steel sheet pile in which the inclination of the flanges on both the upper and lower sides of the concave stepped portion is set so as to be in contact with the radius starting point portion of the outer surface of the flange . The joint flange inclination θ1 that is the inclination of the flange on the lower side of the concave step portion is set to 10 ° or less, and the web side flange inclination θ2 that is the inclination of the flange on the upper side of the concave step portion is the radius of the outer surface of the web side flange. For the angle Ψ calculated by the formula: sin ^-1 (tf2 / h0) from the flange thickness tf2 of the same type steel sheet pile as the stacking partner at the contact point with the starting point and the stacking step interval h0, Ψ− 0.5 ° ~Ψ + 0.5 ° U-type metal sheet piles according to claim 1, characterized in that it is in the range of.

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